Developing system for film by adiabatic heat flow

ABSTRACT

A thermal cavity between heated platens is provided for processing heat-developable film. The platens are controllable to open the cavity and retract from the path of a mechanized film advance.

United States Patent [1 1 [111 3,856,460 Hynes et al. Dec. 24, 1974 DEVELOPING SYSTEM FOR FILM BY ADIABATIC HEAT FLOW [56] References Cited [75] Inventors: Frank R. Hynes, Rochester; Joseph UNITED STATES PATENTS N. May, Webster; David H. 3,038,994 6/1962 Nelson et al. 219/388 UX Thompson, Fairport, all of NY. 3,382,789 5/1968 Barker 95/89 R [73] Assigneez Xerox Corporation, Stamford 3,768,906 10/1973 Michelson et al. 219/216 X Conn Primary Examiner-Fred L. Braun [22] Filed: Nov. 23, 1973 Attorney, Agent, or Firm-Robert J. Bird 21 A l. N 41 ,719 1 PP O 8 57 ABSTRACT A thermal cavity between heated platens is provided 5. 11 for processing heat-developable film. The platens are Field of Search n 95/89 94 controllable to open the cavity and retract from the path of a mechanized film advance.

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PATENTED 3,856,460

sum g5 g DEVELOPER TTME FINISHED STOP FILM ADVANCE DD-ENEDGTZE DEVELOPER SOLENOTD YES DE-ENERGIZE EVELOPE SOLENOID STAT v DEVELOPER OTO I START DEVELOPER MOTOR DEVELOPER "IN POSITION" SWITCH MADE T DEVELOPER "OUT POSITION" SWITCH T MADE YES

STOP YES DEVELOPER MOTOR STOP DEVELOPER MOTOR ENERGIZE DEVELOPER SOLENOTD ENERGIZE DEVELOPER SOLENOID START DEVELOPER TIMER END CYCLE DEVELOPING SYSTEM FOR FILM BY ADIABATIC HEAT FLOW BACKGROUND or THE INVENTION This invention relates to apparatus for developing dry processable film.

In recent years, many types of film have been devised which, upon exposure to light, can be developed by heating the film to or above a predetermined threshold developing temperature. This film is commonly referred to as dry film and is exemplified by a silver halide based film disclosed in U.S. Pat. No. 3,455,075.

One particular method capable of rapidly and efficiently developing a dry film is set out in co-pending U.S. application Ser. No. 377,887, filed on July 9, 1973, by Joseph N. May. This particular method relies upon a heat conductive mechanism to rapidly heat the film above the threshold temperature and an adiabatic heat mechanism to hold the film at the predetermined developing temperature until development is completed. By conductively heating the film when in the transient state the film can be rapidly brought to the developing temperature. Adiabatically heating the film under steady state conditions provides for a relatively uniform development of extremely high density images.

In the May apparatus, the non-emulsion side of the film is tensioned against a heated platen surface. A second platen, which physically complements the first platen, is brought into close non-contacting proximity with the emulsion side of the film. In operation, the second or complementary platen is held at the same temperature as the contact platen whereby an adiabatic heating cavity is formed therebetween.

SUMMARY OF THE INVENTION The primary object of this invention is to adapt the conductive-adiabatic dry film developing system for automatically processing a continuous web of dry film.

A further object of the present invention is to provide a dry film developing apparatus for automatically processing a continuous web of dry film whereby the film is rapidly brought to developing temperatures by means of a conductive heat mechanism and held at the development temperature under adiabatic conditions until development is completed.

These and other objects of the present invention are attained by means of a dry film developing apparatus having a pair of complementary surfaces heated to the same temperature so as to form a developing cavity therebetween, means to move the developing appara tus from a standby position adjacent to a web of dry film in process to an operable position wherein one of the heated surfaces isbrought into contact with the film, and means to rapidly open and close the developing cavity as the developing apparatus moves between the standby position and the operative position whereby the cavity is maintained at a uniform developing temperature.

For a better understanding of the invention as well as other objects and further features thereof, reference is had to the following detailed description of the invention to be read in connection with the accompanying drawings.

DRAWING FIG. I is a plan view illustrating a dry film processor according to the present invention;

FIG. 2 is a side elevation view of .the processor shown from the right side of FIG. 1 illustrating the developing apparatus in a momentary open position;

FIG. 3 is similar to FIG. 2 and illustrates the developing apparatus in a closed operative position with one of the heated platen surfaces in contact with the web of film in process;

FIG. 4 is a partial elevation view of the processor shown from the front of FIG. 1 illustrating the developing apparatus in a momentary open position adjacent to the path of travel of the film;

FIG. 5 is a partial elevation view similar to that shown in FIG. 4 illustrating the developing apparatus in a closed operative position with the web of film being removed for illustrative purposes; and

FIG. 6 is a block diagram of the control system for the dry film processor of this invention.

DESCRIPTION Referring now to FIG. 1, the film processor of the present invention is shown in plan view and generally indicated at 2. Processor 2 includes a stationary frame 4 to define a film path and to guide the movement of tensioning the film web along the film path 6.

A developing station is generally indicated at 18 and is reciprocable relative to the frame 4 on a suitable track 20. Developing station 18 is reciprocated relative to the frame 4 by means of an actuator or motor 22 with associated drive mechanism 24 connected to station 18.

In FIG. 2, a film web 26, after having been exposed and ready for processing, is fed into the processor over guide rollers 28. The film feed is by means of a step movement mechanism, not shown, which advances the film in discrete increments, corresponding to the size of individual film frames. The film feed is stopped at the end of an individual feed stroke by a limit switch, not shown. Developing station 18 includes a lower platen 30 fixed by means of suitable fasteners to a base plate 32 which is mounted for reciprocal movement along track 20. Developing station 18 also includes an upper platen 34 which is operatively connected, by suitable guide rods and compression springs to the plunger 36 of a solenoid mechanism 38, for vertical reciprocation therewith. Developer solenoid 38 is preferably an electrically controlled solenoid and its position in the deenergized state is the raised or retracted position shown in FIG. 2. Solenoid 38, with movable plunger 36 and upper platen 34, is mounted on a horizontal frame member 40 which is secured by means of vertical supports 42 to the base plate 32. Base plate 32, frame member 40, and vertical supports 42 are thus an integral frame movable along track 20 relative to the stationary frame 4. This movable frame comprising elements 32, 40, 42 is operatively connected to the actuator or developer motor by means of the drive mechanism 24. (Refer also to FIGS. 4 and 5.)

FIG. 2 shows the development station 18 at a momentary open and inoperative position relative to the film 26. In this retracted position, upper platen 34 is retracted to open the cavity 44 between platens 30 and 34 to permit the advance of the film.'This open position is momentary or transient; in its operative development position and in its standby position, the development cavity 44 between platens 30 and 34 is closed to conserve heat and to avoid thermal gradients across the cavity. Referring now to FIG. 3, the same arrangement is shown except with the cavity 44 closed by the extension of the solenoid and the lowering of platen 34 toward platen 30. As described in greater detail in Application Ser. No. 377,887, filed July 9, 1973, the upper and lower platen surfaces are both electrically heated under controlled conditions whereby the working surfaces on both platens are elevated to the same temperature. The working temperature of the system is at or preferably above the threshold developing temperature of the film and process. As a result, when the platens are brought together into thermal communication with the film web, the upper platen serves to rapidly heat the film to the desired developing temperature by a conductive heat transfer process and the lower platen maintains an adiabatic steady state condition because of the equal termperatures maintained at the platen working surfaces. Thus, the film is kept at a steady thermal condition throughout the development process.

Referring back to FIG. 1 and to FIG. 6, the motor 22 and solenoid 38 of this apparatus are controlled by limit or position switches 46 and 48 and by the film feed limit switch (not shown) in an automatic sequence control. The automatic control is represented in the block diagram of FIG. 6 showing the control logic. In this arrangement, the film feed limit switch is made to start developer motor 22 to drive the developing station 18 forward into the film path 6 and also to deenergize solenoid 38 to open the cavity 44. At this point, the platens 30 and 34 are advancing over the film 26 as shown in FIG. 2. When platens 30 and 34 are, respectively, under and over the film developer inposition switch or control means 48 is made to stop developer motor 22 and to energize solenoid 38 to extend the plunger 36 and platen 34 down against the film 26 as shown in FIG. 3. After a preset time period, which is on the order of to seconds, switch 48 is made by timer 50 to de-energize solenoid 38 and start motor 22 to return the developing station 18 out of the path of film 26. Finally, position switch or control means 46 is made to stop motor 22 and energize solenoid 38 to close cavity 44 for the rest or standby position of the apparatus. Thus, one complete cycle is performed. In short, the development cavity of developing station 18 is opened and advanced over the film, closed around the film, re-opened and retracted, and closed, completing a film development cycle. Film web 26 is then advanced a discrete amount whereupon the developing or processing cycle is repeated to develop another frame on the film.

In an alternative emobidment, motor 22 and solenoid 38 could simply be actuated by separate, manually operated switches, with timing being completely in the control of the operator. Similarly, the apparatus could be provided for simple manual control without electrical drives. In other words, mechanism 24 could be driven by a hand crank instead of electrical means and plunger 36 with platen 34 could be motivated by mechanical or manual apparatus.

More detail with respect to some of the elements described is set out in other, related patent applications.

Application Ser. No. 377,888, filed on July 9, 1973, by David M. Thompson discloses specific construction of theplaten members 30 and 34. Application Ser. No. 399,590, filed Sept. 21, 1973, by Frank R. Hynes discloses the spring structure connected to roller 12 by which tension on the film 26 is maintained constant. The disclosures in these applications as well as the earlier mentioned application Ser. No. 377,887, are hereby incorporated by reference in this specification.

The foregoing description of an embodiment of this invention is given by way of illustration and not of limitation. The concept and scope of the invention are limited only by the following claims and equivalents thereof which may occur to others skilled in the art.

What is claimed is:

1. Developing apparatus for processing a web of dry film having a heat developable emulsion on one side of a support material, including:

a frame to support and guide a web of film in tension along a film path, a developing station movably mounted on said frame and operatively connected to a drive means for reciprocating movement along a first axis between a standby position and an operative position relative to said film path, said developing station including a pair of heatable platens having substantially mating facing surfaces defining a cavity therebetween and actuator means to effect reciprocating movement of one of said platens relative to the other of said platens along a second axis to respectively close and open said cavy. said platens being disposed one on each side of said film when said developing station is in its operative position relative to said film path, said platens being out of contact with said film when said cavity is open, and one of said platens being in contact with the side of said film opposite said emulsion when said cavity is closed, and control means interconnecting said drive means and said actuator means to interdependently control: 1. said drive means to move said developing station to and from its operative position relative to said film path, and

2. said actuator means to open and close said cavity.

2. Developing apparatus as defined in claim I in which said first and second axes are substantially perpendicular to each other and to said film path.

3. Developing apparatus as defined in claim 1 in which said drive means and said actuator means are electrical actuators.

4. Developing apparatus for processing a web of dry film having a heat developable emulsion on one side of a support material, including:

a. a frame including a plurality of rollers to support and guide a web of film in tension along a film path,

b. a developing station movably mounted on a track on said frame and operatively connected to a drive motor for reciprocating movement along a first axis between a standby position and an operative position relative to said film path, said developing station including:

i. a pair of heatable platens having substantially mating facing surfaces defining a cavity therebetween, and

ii. actuator means to reciprocate at least one of said platens along a second axis between an open cavity position and a closed cavity position relative to the other of said platens,

said platens being disposed one on each side of said film when said developing station is in said operative position, said platens being out of contact with said film when said cavity is open to permit advancement of said film along said film path or movement of said developing station along said track, and one of said platens being in contact with the side of said film opposite said emulsion for holding said film in close non-contacting proximity to the other of said platens when said cavity is closed, and

c. control means interconnecting said drive motor and said actuator means to interdependently control:

i. said drive motor to move said developing station to and from its operative position relative to said film path, and

ii. said actuator means to open and close said cavity.

5. Developing apparatus as defined in claim 4 in which said drive motor and said actuator means are electrical actuators and in which said control means includes:

start control means to start said drive motor and open said cavity at said standby position,

first control means responsive to the presence of said developing station at its operative position to stop said drive motor and close said cavity,

timer means responsive to the passage of a predetermined time span after the closure of said cavity at said operative position to open said cavity and start said drive motor and,

second control means responsive to the presence of said developing station at its standby position, to stop said drive motor and close said cavity.

6. Developing apparatus for processing a web of dry film having a heat developable emulsion on one side of a support material, including:

a frame to support and guide a web of film in tension along a film path,

a cylindrical compliance roll rotatably mounted in slotted apertures for rotation and lateral translation relative to said frame, said compliance roll positioned for rolling contact with said film and being biased against said film to maintain said film in constant tension with changes in the geometry of said film path,

said bias being by means of a compression spring of substantially constant compression force throughout its displacement operatively connected between said frame and said compliance roll,

a developing station movably mounted on said frame and operatively connected to a drive means for reciprocating movement along a first axis between a standby position and an operative position relative to said film path,

said developing station including a pair of heatable platens having substantially mating facing surfaces defining a cavity therebetween and actuator means to effect reciprocating movement of one of said platens relative to the other of said platens along a second axis to respectively close and open said cavity,

said platens being disposed one on each side of said film when said developing station is in operative position relative to said film path, said platens being out of contact with said film when said cavity is open, and one of said platens being in contact with the side of said film opposite said emulsion when said cavity is closed. 

1. Developing apparatus for processing a web of dry film having a heat developable emulsion on one side of a support material, including: a frame to support and guide a web of film in tension along a film path, a developing station movably mounted on said frame and operatively connected to a drive means for reciprocating movement along a first axis between a standby position and an operative position relative to said film path, said developing station including a pair of heatable platens having suBstantially mating facing surfaces defining a cavity therebetween and actuator means to effect reciprocating movement of one of said platens relative to the other of said platens along a second axis to respectively close and open said cavity, said platens being disposed one on each side of said film when said developing station is in its operative position relative to said film path, said platens being out of contact with said film when said cavity is open, and one of said platens being in contact with the side of said film opposite said emulsion when said cavity is closed, and control means interconnecting said drive means and said actuator means to interdependently control:
 1. said drive means to move said developing station to and from its operative position relative to said film path, and
 2. said actuator means to open and close said cavity.
 2. said actuator means to open and close said cavity.
 2. Developing apparatus as defined in claim 1 in which said first and second axes are substantially perpendicular to each other and to said film path.
 3. Developing apparatus as defined in claim 1 in which said drive means and said actuator means are electrical actuators.
 4. Developing apparatus for processing a web of dry film having a heat developable emulsion on one side of a support material, including: a. a frame including a plurality of rollers to support and guide a web of film in tension along a film path, b. a developing station movably mounted on a track on said frame and operatively connected to a drive motor for reciprocating movement along a first axis between a standby position and an operative position relative to said film path, said developing station including: i. a pair of heatable platens having substantially mating facing surfaces defining a cavity therebetween, and ii. actuator means to reciprocate at least one of said platens along a second axis between an open cavity position and a closed cavity position relative to the other of said platens, said platens being disposed one on each side of said film when said developing station is in said operative position, said platens being out of contact with said film when said cavity is open to permit advancement of said film along said film path or movement of said developing station along said track, and one of said platens being in contact with the side of said film opposite said emulsion for holding said film in close non-contacting proximity to the other of said platens when said cavity is closed, and c. control means interconnecting said drive motor and said actuator means to interdependently control: i. said drive motor to move said developing station to and from its operative position relative to said film path, and ii. said actuator means to open and close said cavity.
 5. Developing apparatus as defined in claim 4 in which said drive motor and said actuator means are electrical actuators and in which said control means includes: start control means to start said drive motor and open said cavity at said standby position, first control means responsive to the presence of said developing station at its operative position to stop said drive motor and close said cavity, timer means responsive to the passage of a predetermined time span after the closure of said cavity at said operative position to open said cavity and start said drive motor and, second control means responsive to the presence of said developing station at its standby position, to stop said drive motor and close said cavity.
 6. Developing apparatus for processing a web of dry film having a heat developable emulsion on one side of a support material, including: a frame to support and guide a web of film in tension along a film path, a cylindrical compliance roll rotatably mounted in slotted apertures for rotation and lateral translation relative to said frame, said compliance roll positioned for rolling contact with said film and being biased against said film to maintain said filM in constant tension with changes in the geometry of said film path, said bias being by means of a compression spring of substantially constant compression force throughout its displacement operatively connected between said frame and said compliance roll, a developing station movably mounted on said frame and operatively connected to a drive means for reciprocating movement along a first axis between a standby position and an operative position relative to said film path, said developing station including a pair of heatable platens having substantially mating facing surfaces defining a cavity therebetween and actuator means to effect reciprocating movement of one of said platens relative to the other of said platens along a second axis to respectively close and open said cavity, said platens being disposed one on each side of said film when said developing station is in operative position relative to said film path, said platens being out of contact with said film when said cavity is open, and one of said platens being in contact with the side of said film opposite said emulsion when said cavity is closed. 